5.4 Abstract - FLOW CYTOMETRY (Core Group A) The Flow Cytometry Shared Resource (Core Group A) offers Cancer Center users multi-parametric evaluation and high-speed enrichment of phenotypically distinct cell populations using flow cytometry. For analytical flow cytometry, investigators have a choice of full-service analysis, or receiving training for independent use of four analytical flow cytometers (BD LSRFortessa, BD FACSCanto, BD FACSCalibur, Millipore Muse). Investigator training and consulting is also provided on analytical software including FACSDiVa, CellQuest, FlowJo, and ModFitLT. For high-speed cell sorting, the Core provides experimental planning and full-service cell sorting by two expert operators, utilizing two BD FACSAria sorters in biosafety cabinets. The Resource is staffed by two full-time cytometrists with a combined 18 years of experience in NCI- designated Cancer Center flow cytometry cores. Resource staff provide investigators with extensive flow cytometry guidance, from experimental set-up, selection of reagents, setting gating or sorting parameters, data interpretation, and development of new methods. The Core is widely used and, as in the past funding period, services were provided for over 40 Cancer Center members, representing all three Programs, and Flow Cytometry supported key experiments described in at least 91 cancer-relevant publications from Cancer Center members. There have been quite dramatic upgrades to the Core in the past funding period. A half-time staff member assisting the Director was replaced by an accomplished full-time cytometrist, and the Resource implemented iLab web-based software to streamline Core scheduling, project management, and billing. Technology upgrades to the core include the addition of two BD FACSAria sorters (11-color and 16-color) housed in custom biosafety cabinets, a 14-color BD LSRFortessa analyzer with a 96 well plate-loader, and a Millipore Muse Cell Analyzer. An Amnis ImageStreamX Mark II imaging cytometer was purchased and will be installed in May 2014. This instrument with three lasers combines flow cytometry with high resolution microscopy to enable spatial and morphological analysis of cells in flow, including rare cells. Plans for future development of the Resource include evaluation of hardware for time-of-flight mass cytometry, microfluidic sorting of circulating tumor cells, and automated magnetic separation.